Can't kill $MAINPID in Tomcat (code=exited, status=1/FAILURE)

I follow the Digital Ocean Guide How To Install Apache Tomcat 8 on CentOS 7? https://www.digitalocean.com/community/tutorials/how-to-install-apache-tomcat-8-on-centos-7
Because I want to able to run Tomcat as a service. But in the config file(/etc/systemd/system/tomcat.service) there is a wrong part:
I got folowing error if I get the command:
*systemctl tomcat status:
*ExecStop=/bin/kill -15 $MAINPID (code=exited, status=1/FAILURE)
here is the content of the file: